1. Field of Invention
The embodiment of the present invention relates generally to a heat-insulating film and, more particularly, to a heat-insulating film having a cholesteric liquid crystal layer.
2. Description of Related Art
In recent years, the demand for more convenient, robust and economical goods has continued to rise along with the increase in socio-economic standards. Technological advances and progress in industry have provided the means to meet such a demand. Nevertheless, products with more economic value and other advantages continue to be developed to meet these and other needs.
The principal purpose of heat-insulating films is to retard the flow of heat. Heat-insulating films are commonly installed on windows of transportation vehicles and buildings. Statistics indicate that energy for air conditioning accounts for about 47% of the total energy consumption in commercial buildings. Accordingly, strategies for reducing electricity demand are important in reducing the operating costs of a building.
The infrared component of sunlight is the main natural heat source. When the infrared component of sunlight enters a building, a rise in the temperature inside the building generally results. Therefore, air conditioning is required to lower the room temperature in commercial buildings.
Heat-insulating films are commonly attached to windows of commercial buildings to reduce the radiation level entering the buildings. However, conventional heat-insulating films block both the infrared component and the visible light component of sunlight. The reduced transmission of the visible light component leads to a reduction in brightness in commercial buildings.
In view of the foregoing, conventional heat-insulating films have several drawbacks associated therewith, and a solution to these problems has been long awaited by the industry. Accordingly, there exists a need in the art for providing heat-insulating films capable of blocking the incidence of infrared light while allowing visible light to pass therethrough.